j90tsleua 20in model

[stump32046]

I have replaced the head gaskets and water deflectors but did not open the exhaust cover due to a couple of broken bolts. The engine runs hot at WOT, pulled hose from heads and on mickey mouse ears, the port head has about 3/8 dia stream from it and is warm. The stbd head has a trickle to 1/4 stream and is steaming. OK, I am looking at a water restriction .
I do not want to bust open the exh cover and take a week drilling out bolts.
Question is, has anyone had success flusing out the eng with a high concentration of vinegar or CLR or Lime Away? If I need to mechanically clean the passages, I will.

 

[emdsapmgr]

Did you consider replacing the thermostats? That engine has one thermostat to control the temp in each head. Sounds like one of them may be stuck shut. If you decide to replace one stat, do them both.

 

[stump32046]

I had pulled the thermostats when this first started happening

 

[flyingscott]

What about the waterpump

 

[stump32046]

Water pump has been replaced a couple of times

 

[emdsapmgr]

Did you pull the cylinder head cover off the starboard head to see if the internal cooling passages are clear?